The effect of plant light environment on mycorrhizal colonisation in field‐grown seedlings of podocarp‐angiosperm forest tree species

Abstract

To test the possibility that the development of mycorrhizas in seedlings may be limited under shaded conditions, arbuscular mycorrhizal colonisation was measured in gap and understorey seedlings from mixed podocarp/angiosperm forests in North Okarito, south Westland, and Blue Duck Scientific Reserve, Marlborough, New Zealand. Mean percentage colonisation of seedlings of podocarp and angiosperm tree species ranged from 66 to 97% of root length, and no seedlings were nonmycorrhizal. Plant light environment had no significant overall effect on percentage mycorrhizal colonisation within cortical cells. Levels of colonisation of seedlings at North Okarito forest, which experiences high annual rainfall and grows on a poorly drained gley-podzol soil, were similar to those of seedlings from Blue Duck Scientific Reserve, a podocarp-angiosperm forest of comparable structure, which experiences much lower annual rainfall and grows on soils dominated by yellowbrown earths of moderate to high fertility. This result B00032 indicates that all podocarp and angiosperm seedlings in forests of this type in New Zealand are likely to support heavy arbuscular mycorrhizal colonisation, regardless of regional climatic conditions and soil type.

Plant–soil feedbacks and the dominance of conifers in a tropical montane forest in Borneo

“…Indeed, as shown in previous studies (Hurst et al. , Dickie and Holdaway ), AMF infection of conifer (podocarp) roots is generally extremely dense. For example, Hurst et al.…”

“…Indeed, as shown in previous studies (Hurst et al 2002, Dickie andHoldaway 2011), AMF infection of conifer (podocarp) roots is generally extremely dense. For example, Hurst et al (2002) reported infection levels of 88-96% of root length of New Zealand temperate podocarps. This type of root structure specific to podocarps (or Araucariaceae), dense AMF infections and the compositions of the mycorrhizal fungal community specific to podocarps (or Araucariaceae) might explain the finding that AMassociated conifers are more efficient in N uptake than EM-associated trees in our study.…”

The hare, the tortoise and the crocodile: the ecology of angiosperm dominance, conifer persistence and fern filtering

“…1963; Russell et al . 2002), which efficiently take up phosphate, the majority of angiosperm species in mixed lowland rain forests are also heavily infected (Hurst et al . 2002).…”

“…Enright & Ogden 1995). However, although podocarps are heavily infected with endomycorrhizal associates (Baylis et al 1963;Russell et al 2002), which efficiently take up phosphate, the majority of angiosperm species in mixed lowland rain forests are also heavily infected (Hurst et al 2002).…”

Efeito da disponibilidade de água e de luz na colonização micorrízica e no crescimento de Tabebuia avellanedae Lorentz ex Griseb. (Bignoniaceae)

“…Nesses ambientes, disponibilidade de luz, de água e de nutrientes varia no tempo e espaço e é considerado o fator abiótico que mais afeta o estabelecimento das plântulas (EVANS e EDWARDS, 2001). A capacidade da espécie em adequarse morfológica e fisiologicamente às variações na disponibilidade de recursos e em associar-se com fungos micorrízicos arbusculares (FMA) favorece o estabelecimento de plantas em ambientes limitantes em água e luz (EVANS e EDWARDS, 2001;HURST et al, 2002). No entanto, também a associação micorrízica entre raízes e FMA é influenciada, entre outros fatores, pela intensidade de luz (GEHRING, 2003) e pela disponibilidade de água (ENTRY et al, 2002).…”